/*
 * Copyright 1999-2011 Alibaba Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.dubbo.remoting.exchange.support.header;

import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.remoting.Client;
import com.alibaba.dubbo.remoting.RemotingException;
import com.alibaba.dubbo.remoting.Server;
import com.alibaba.dubbo.remoting.Transporters;
import com.alibaba.dubbo.remoting.exchange.ExchangeClient;
import com.alibaba.dubbo.remoting.exchange.ExchangeHandler;
import com.alibaba.dubbo.remoting.exchange.ExchangeServer;
import com.alibaba.dubbo.remoting.exchange.Exchanger;
import com.alibaba.dubbo.remoting.transport.DecodeHandler;

/**
 * DefaultMessenger
 *
 * @author william.liangf
 */
public class HeaderExchanger implements Exchanger {

    public static final String NAME = "header";

    @Override
    public ExchangeClient connect(URL url, ExchangeHandler handler) throws RemotingException {

        // 开启一个Transporters的客户端
        // 解码handler  包装 心跳handler  包装  原始的handler    【装饰者模式】
        HeaderExchangeHandler headerExchangeHandler = new HeaderExchangeHandler(handler);
        DecodeHandler decodeHandler = new DecodeHandler(headerExchangeHandler);

        // 传输层：链接服务器，并传入一个处理器
        Client client = Transporters.connect(url, decodeHandler);
        
        return new HeaderExchangeClient(client);
    }

    @Override
    public ExchangeServer bind(URL url, ExchangeHandler handler) throws RemotingException {
        // 【装饰者模式】
        HeaderExchangeHandler headerExchangeHandler = new HeaderExchangeHandler(handler);
        DecodeHandler decodeHandler = new DecodeHandler(headerExchangeHandler);

        Server server = Transporters.bind(url, decodeHandler);

        HeaderExchangeServer headerExchangeServer = new HeaderExchangeServer(server);
        return headerExchangeServer;
    }

}